[求助]OpenDialog打开ESRI GRID文件(c#+ae)问题

<P>我想利用OpenDialog打开ESRI GRID文件，却实现不了？请教大虾帮助。c#+ae代码如下：</P>
<P>OpenFileDialog filedlg_addraster = new OpenFileDialog();<BR>filedlg_addraster.Filter = "ESRI GRID|<GRID>|All Files|*.*";<BR>if (filedlg_addraster.ShowDialog() == DialogResult.OK)<BR>            {<BR>                string m_FileName = Path.GetFileName(filedlg_addraster.FileName);<BR>                string m_FilePath = Path.GetDirectoryName(filedlg_addraster.FileName);<BR>                IWorkspaceFactory iWsFactory = new RasterWorkspaceFactoryClass();<BR>                IRasterWorkspace iRasWs;<BR>                if(iWsFactory.IsWorkspace(m_FilePath))<BR>                {<BR>                    iRasWs = (IRasterWorkspace)iWsFactory.OpenFromFile(m_FilePath, 0);<BR>                    IRasterDataset iRasDs = iRasWs.OpenRasterDataset(m_FileName);                <BR>                    IRasterLayer iRLayer = new RasterLayerClass();                    <BR>                    iRLayer.CreateFromDataset(iRasDs);<BR>                    ILayer iLayer = iRLayer;<BR>                    axMapControl1.AddLayer(iLayer, 0);<BR>                }</P>